A Novel Missense Variant in the ESRRB Gene Causing Nonsyndromic Hearing Loss: In Silico Analyses of a Case

Background: Genetic hearing loss (GHL) is a common heterogeneous disorder that can affect all ages, ethnicities, and genders. The most common form of hearing loss (HL) is autosomal recessive non-syndromic hearing loss (ARNSHL) and in most cases specific genotype-phenotype correlation is indistinguishable. This study aimed to identify the genetic cause of hearing loss in an Iranian Azeri Turkish ethnicity family with consanguine marriage which is negative for GJB2, GJB6 and mitochondrially encoded 12S RRNA (MT-RNR1) deleterious mutations. Methods: Targeted genome sequencing was applied for the detection of possible genetic causes of HL in this family. Co-segregation and in silico analysis of variant was performed by standard procedure. Results: A missense variant, c.499G>A, was identified in the ESRRB gene. Healthy and affected members of the family confirmed co-segregation of the variant with ARNSHL in the pedigree and then the pathogenicity of the variant was confirmed by in silico analysis and ACMG Guidelines. Conclusion: We report a novel missense variant in the ESRRB gene which seems to be a pathogenic variant. The result of this study suggests that the genetic background of hearing loss patients plays important role in the pathogenicity; moreover, targeted genomic capture is a powerful method that can discover pathogenic variants in heterogeneous disorders.